Olefin-based resin preparations

Abstract

The invention relates to an olefin-based resin composition comprising: 9.7 to 36 parts by mass of unmodified olefin-based polymer (A), 0.3 to 15 parts by mass of acid-modified propylene-based polymer (B), and 54 to 90 parts by mass of metal oxide (C), provided that the total amount of unmodified olefin-based polymer (A), acid-modified propylene-based polymer (B), and metal oxide (C) is 100 parts by mass; and 0.1 to 10 parts by mass of unmodified polyolefin-based wax (D), over a total of 100 parts by mass of unmodified olefin-based polymer (A), acid-modified propylene-based polymer (B), and metal oxide (C).

Description

Olefin-based resin composition and its uses

[0001] The present invention relates to an olefin resin composition containing a metal oxide and its use.

[0002] Olefin polymers are molded by various methods and used in a wide range of applications. However, polyolefins such as polypropylene are inferior to engineering plastics (engineering plastics) such as polyamides and polycarbonates in terms of heat resistance, rigidity, tensile strength, and other mechanical properties, and therefore, depending on the application, inorganic fillers such as talc, and heat-resistant fibers such as glass fibers and carbon fibers are blended (added) as reinforcing materials.

[0003] For example, Patent Document 1 proposes a polyolefin composition containing a large amount of inorganic filler (20 to 80 parts by weight) made of an inorganic compound, and teaches that adding a silane-modified polyolefin improves moldability and prevents sheet sagging. On the other hand, it has been found that when a large amount of inorganic compound such as metal oxide is blended, the kneadability with polyolefin is poor. To improve the kneadability, for example, Patent Document 2 proposes blending 0.1 to 20 parts by mass of a modified polyolefin wax into a composition consisting of 10 to 50 parts by mass of a thermoplastic resin and 50 to 90 parts by mass of a metal oxide.

[0004] Japanese Patent Application Laid-Open No. 52-15542 International Publication No. 2017 / 209215 International Publication No. 2023 / 282327

[0005] However, it has been found that olefin resin compositions obtained by blending modified polyolefin waxes tend to have a relatively high hydroxyl group density on the surface of the resulting molded article, which increases hydrophilicity and results in a moist texture. Furthermore, under certain conditions (such as in an acid solution), inorganic compounds may be eluted, resulting in a deterioration in texture. In light of this, the present applicant has discovered and proposed a resin composition containing a thermoplastic resin such as polyolefin, a metal oxide, and an unmodified polyolefin wax, which has excellent non-water absorption and a hard texture (see Patent Document 3). However, further improvement in strength is desired for application in a variety of applications.

[0006] The object of the present invention is to provide an olefin-based resin composition suitable for obtaining a molded article having excellent strength, without increasing hydrophilicity (low water absorption), a hard texture, and a luxurious texture closer to that of pottery, and a molded article containing the same.

[0007] The present invention relates to, for example, the following items [1] to

[15] : [1] An olefin-based resin composition comprising 9.7 to 36 parts by mass of an unmodified olefin-based polymer (A), 0.3 to 15 parts by mass of an acid-modified propylene-based polymer (B), 54 to 90 parts by mass of a metal oxide (C) (wherein the total amount of the unmodified olefin-based polymer (A), the acid-modified propylene-based polymer (B), and the metal oxide (C) is 100 parts by mass), and 0.1 to 10 parts by mass of an unmodified polyolefin-based wax (D) relative to a total of 100 parts by mass of the unmodified olefin-based polymer (A), the acid-modified propylene-based polymer (B), and the metal oxide (C).

[0008] [2] The olefin-based resin composition according to [1], wherein the unmodified olefin-based polymer (A) is at least one selected from the group consisting of an ethylene-based polymer, a propylene-based polymer, a 1-butene-based polymer, and a 4-methyl-1-pentene-based polymer. [3] The olefin-based resin composition according to [1] or [2], wherein the metal oxide (C) comprises magnesium oxide.

[0009] [4] The olefin-based resin composition according to any one of [1] to [3], wherein the thermal conductivity of the metal oxide (C) is in the range of 10 to 300 W / mK. [5] The olefin-based resin composition according to any one of [1] to [4], wherein the thermal conductivity of the olefin-based resin composition is in the range of 0.5 to 5 W / mK. [6] The olefin-based resin composition according to any one of [1] to [5], wherein the specific gravity of the olefin-based resin composition is in the range of 1.2 to 5.0.

[0010] [7] The olefin-based resin composition according to any one of [1] to [6], wherein the content of unsaturated carboxylic acid in the olefin-based resin composition is in the range of 0.002 to 0.42 parts by mass per 100 parts by mass of the total of the unmodified olefin-based polymer (A), the acid-modified propylene-based polymer (B), the metal oxide (C), and the unmodified polyolefin-based wax (D). [8] A molded article comprising the olefin-based resin composition according to any one of [1] to [7]. [9] A door handle, door knob, handrail, or switch comprising the olefin-based resin composition according to any one of [1] to [7].

[10] A housing comprising the olefin-based resin composition according to any one of [1] to [7].

[0011]

[11] An electricity storage device comprising the olefin resin composition according to any one of [1] to [7].

[12] A clothing accessory comprising the olefin resin composition according to any one of [1] to [7].

[0012]

[13] Stationery comprising the olefin resin composition according to any one of [1] to [7].

[14] A container, tableware or sake cup comprising the olefin resin composition according to any one of [1] to [7].

[15] A mouse or keyboard comprising the olefin resin composition according to any one of [1] to [7].

[0013] The olefin resin composition of the present invention is suitable for producing molded articles that have extremely low water absorption and excellent non-absorbency, and have thermal conductivity equivalent to that of ceramic, resulting in a cool feel and a hard texture, a texture more similar to that of ceramic, a luxurious feel, and excellent strength in terms of surface hardness, tensile strength, impact strength, flexural strength, etc. The molded articles of the present invention are suitable for a variety of applications, such as door handles, door knobs, handrails or switches, housings for home appliances and the like, electricity storage devices, clothing accessories, containers, stationery, tableware, sake cups, mice or keyboards, and have extremely low water absorption and excellent non-absorbency, a texture similar to that of ceramic, such as a cool feel and a hard texture, and can be suitably used for applications that involve touching with the hands.

[0014] The present invention will be specifically described below. In this specification, the term "polymer" includes homopolymers and copolymers unless otherwise specified.

[0015] [Olefin Resin Composition] The olefin resin composition of the present invention contains, as essential components, an unmodified olefin polymer (A), an acid-modified propylene polymer (B), a metal oxide (C), and an unmodified polyolefin wax (D).

[0016] <Unmodified Olefin Polymer (A)> The unmodified olefin polymer (A) (hereinafter also simply referred to as olefin polymer (A)) constituting the olefin resin composition of the present invention is an olefin polymer that has not been acid-modified or graft-modified, and is a polymer containing an α-olefin as the main component, such as a homopolymer of an α-olefin (including ethylene) such as ethylene, propylene, 1-butene, or 4-methyl-1-pentene, a copolymer of an α-olefin with another α-olefin, or a copolymer of an α-olefin with a monomer other than an α-olefin.

[0017] The monomer constituting the olefin polymer (A) (for example, an α-olefin such as propylene) can be derived from any of fossil fuels, biomass, and chemically recycled materials. Furthermore, as the raw material monomer for the olefin polymer (A), a combination of raw materials derived from fossil fuels and biomass, a combination of raw materials derived from fossil fuels and chemically recycled materials, a combination of raw materials derived from biomass and chemically recycled materials, or a combination of raw materials derived from fossil fuels, biomass, and chemically recycled materials may be used.

[0018] Specific examples of the olefin polymer (A) according to the present invention include the following polymers (A1) to (A4).

[0019] <Ethylene-Based Polymer (A1)> The ethylene-based polymer (A1) is a homopolymer of ethylene or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, and examples thereof include polymers containing ethylene-derived structural units as the main component (containing 51 to 100 mol % of ethylene), which are usually called high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ethylene-α-olefin copolymers. Specific examples of the α-olefin having 3 to 20 carbon atoms to be copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 2-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3,5,5-trimethyl-1-hexene, etc. Among these, α-olefins having 3 to 10 carbon atoms are preferred, α-olefins having 3 to 8 carbon atoms are more preferred, and ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are even more preferred. The molar ratio of ethylene to α-olefin (ethylene / α-olefin) is preferably 99 / 1 to 60 / 40, more preferably 95 / 5 to 70 / 30, and even more preferably 90 / 10 to 60 / 25.

[0020] Specific preferred examples of the ethylene-α-olefin copolymer include an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-4-methyl-1-pentene copolymer, an ethylene-1-octene copolymer, an ethylene-propylene-1-butene copolymer, and an ethylene-propylene-1-octene copolymer. Among these, an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-4-methyl-1-pentene copolymer, and an ethylene-1-octene copolymer are preferred, and an ethylene-1-butene copolymer is more preferred.

[0021] The density of the ethylene polymer (A1) (measured according to JIS K7112) is preferably 850 to 980 kg / m 3 , more preferably 855 to 978 kg / m 3 , more preferably 860 to 976 kg / m 3 , particularly preferably 862 to 973 kg / m 3 is.

[0022] When the olefin resin composition of the present invention contains an ethylene polymer (A1), a molded article obtained from the olefin resin composition has higher thermal conductivity, an excellent warm / cold sensation, and tends to emit a high-pitched sound when struck, compared to a molded article obtained from the olefin resin composition containing a propylene polymer (A2) described later. Such a molded article can be suitably used for various applications without limitation, and can be suitably used, for example, as a base material for surface modification by metal vapor deposition.

[0023] <Propylene-Based Polymer (A2)> The propylene-based polymer (A2) is a polymer containing, as a main component (containing 51 to 100 mol % of propylene), a structural unit derived from propylene, such as a homopolymer of propylene (propylene homopolymer: homo PP), a copolymer of propylene with ethylene and / or an α-olefin having 4 to 20 carbon atoms (random copolymer: random PP), or a composition of a propylene homopolymer and an ethylene-propylene copolymer (block copolymer: block PP), Specific examples of the α-olefin in the olefin-α-olefin copolymer include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 2-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1-hexene, 3,5,5-trimethyl-1-hexene, etc. Among these, ethylene and α-olefins having 4 to 10 carbon atoms are preferred, ethylene and α-olefins having 4 to 8 carbon atoms are more preferred, ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are even more preferred, and ethylene is particularly preferred. The molar ratio of propylene to α-olefin (propylene / α-olefin) is preferably 99 / 1 to 60 / 40, more preferably 95 / 5 to 70 / 30, and even more preferably 90 / 10 to 70 / 30.

[0024] Specific preferred examples of the propylene-α-olefin copolymer (random PP) include a propylene-ethylene copolymer, a propylene-1-butene copolymer, a propylene-1-hexene copolymer, a propylene-4-methyl-1-pentene copolymer, a propylene-1-octene copolymer, and a propylene-ethylene-1-butene copolymer. Of these, a propylene-ethylene copolymer and a propylene-1-butene copolymer are preferred, and a propylene-ethylene copolymer is particularly preferred.

[0025] In the case of a propylene homopolymer, the melting point is preferably 155 to 170°C, more preferably 158 to 165°C. In the case of a propylene-ethylene random copolymer, the ethylene content of the propylene-ethylene random copolymer is preferably 1.9 to 5.4% by mass, more preferably 2.0 to 4.8% by mass. The crystalline melting point of the propylene-ethylene random copolymer, measured by differential scanning calorimetry (DSC) in accordance with JIS K7121, is preferably usually 130 to 150°C, more preferably 130 to 145°C, and particularly preferably 135 to 145°C.

[0026] The density of the propylene polymer (A2) (measured according to JIS K7112) is preferably 850 to 910 kg / m 3 and more preferably 875 to 909 kg / m 3 and more preferably 890 to 908 kg / m 3 is.

[0027] As the propylene polymer (A2), for example, a propylene-ethylene block copolymer and a propylene-ethylene random copolymer may be used alone or in combination of two or more copolymers. For example, two or more copolymers may be mixed to adjust the MFR. When the olefin resin composition of the present invention contains the propylene polymer (A2) as the olefin polymer (A), a molded article obtained from the olefin resin composition of the present invention can be suitably used for various applications without limitation. However, since the molded article has a thermal conductivity close to that of ceramics and a specific gravity equivalent to that of ceramics, and is not easily broken even when subjected to impacts such as dropping, unlike ceramics, and is therefore highly safe, it can be suitably used for applications that involve contact with hands, such as tableware such as cups, containers, and door handles.

[0028] <1-Butene Polymer (A3)> The 1-butene polymer (A3) is a polymer containing, as a main component (containing 51 to 100 mol % of 1-butene), structural units derived from 1-butene, such as a homopolymer of 1-butene (polybutene) or a copolymer of 1-butene with ethylene, propylene, and an α-olefin having 5 to 20 carbon atoms (1-butene-α-olefin copolymer).

[0029] <4-Methyl-1-pentene Polymer (A4)> The 4-methyl-1-pentene polymer (A4) is a polymer containing, as a main component (containing 51 to 100 mol % of 4-methyl-1-pentene), structural units derived from 4-methyl-1-pentene, such as a homopolymer of 4-methyl-1-pentene and a copolymer of 4-methyl-1-pentene with an α-olefin having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene) (4-methyl-1-pentene-α-olefin copolymer).

[0030] Specific examples of the α-olefin in the 4-methyl-1-pentene / α-olefin copolymer include linear α-olefins having 2 to 20 carbon atoms (preferably 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms), such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene; and branched α-olefins having 5 to 20 carbon atoms (preferably 5 to 15 carbon atoms), such as 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, and 3-ethyl-1-hexene. Among these, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene are preferred, with ethylene and propylene being particularly preferred. The α-olefin may be derived from one of these compounds, or from two or more of these compounds. The molar ratio of 4-methyl-1-pentene to the α-olefin (4-methyl-1-pentene / α-olefin) is preferably 55 / 45 to 90 / 10, more preferably 60 / 40 to 86 / 14, and even more preferably 68 / 32 to 85 / 15.

[0031] In one embodiment, the 4-methyl-1-pentene polymer (A4) has a peak temperature of 0°C or higher and 60°C or lower, preferably 10°C or higher and 50°C or lower, more preferably 20°C or higher and 45°C or lower, and particularly preferably 25°C or higher and 44°C or lower, at which the loss tangent (tan δ) obtained by dynamic viscoelasticity measurement in a temperature range of −40 to 150°C at a frequency of 10 rad / s (1.6 Hz) reaches a peak temperature.

[0032] The 4-methyl-1-pentene polymer (A4) has a peak value of tan δ of 0.6 or more and 5.0 or less, preferably 0.7 or more and 4.5 or less, and more preferably 0.8 or more and 3.5 or less.

[0033] Tan δ can be calculated as the ratio of the storage modulus (G') to the loss modulus (G") (G" / G': loss tangent) using the storage modulus (G') and loss modulus (G") obtained during measurement of dynamic viscoelasticity.

[0034] In the present invention, the temperature at which tan δ reaches its peak value (maximum value) in the range of −40 to 150° C. is defined as the temperature at which tan δ reaches its peak value (hereinafter referred to as the “tan δ peak temperature”), and the value of tan δ at that time is defined as the peak value of tan δ (hereinafter referred to as the “tan δ peak value”). The peak is considered to be due to the glass transition temperature of the 4-methyl-1-pentene polymer (A4).

[0035] In another embodiment, the 4-methyl-1-pentene polymer (A4) preferably has a tan δ peak temperature of 15°C or higher and 45°C or lower, as determined by dynamic viscoelasticity measurement at a frequency of 10 rad / s (1.6 Hz) in a temperature range of -40 to 150°C. Regarding the lower limit of the tan δ peak temperature, the tan δ peak temperature is more preferably 20°C or higher, and even more preferably 25°C or higher. In an exemplary embodiment of the present invention, the tan δ peak temperature is 40°C or lower, but may exceed 40°C as long as the object of the present invention is achieved. In a typical embodiment of the present invention, the tan δ peak temperature is more preferably 20°C or higher and 45°C or lower, and even more preferably 25°C or higher and 43°C or lower. By setting the tan δ peak temperature within the above temperature range, the tan δ value at room temperature can be further increased.

[0036] The 4-methyl-1-pentene polymer (A4) preferably has a tan δ peak value of 0.6 or more and 5.0 or less, more preferably 1.0 or more and 4.8 or less, even more preferably 1.3 or more and 4.5 or less, and particularly preferably 1.8 or more and 4.0 or less, as determined by dynamic viscoelasticity measurement at a frequency of 10 rad / s (1.6 Hz) in a temperature range of −40 to 150° C. By controlling the tan δ peak value within the above range, it is possible to change the vibration absorption properties, hardness and conformability of the material depending on the rate of tension or deformation.

[0037] The 4-methyl-1-pentene polymer (A4) preferably has a melting point (Tm) measured by a differential scanning calorimeter (DSC) of 160° C. or lower or not observable, more preferably 140° C. or lower or not observable, and even more preferably not observable. By satisfying these requirements, the resin composition of the present invention can be easily kneaded with an inorganic substance such as a metal oxide (C), and the vibration absorption property and stress relaxation property can be improved.

[0038] The 4-methyl-1-pentene polymer (A4) preferably has an intrinsic viscosity [η] measured in decalin at 135° C. of 0.1 dL / g or more and 5.0 dL / g or less, more preferably 0.5 dL / g or more and 4.0 dL / g or less, and even more preferably 0.5 dL / g or more and 3.5 dL / g or less. When the 4-methyl-1-pentene polymer (A4) has an intrinsic viscosity [η] within the above range, a molded article can be easily produced.

[0039] The intrinsic viscosity [η] of the 4-methyl-1-pentene polymer (A4) can be adjusted to fall within the above range by adding hydrogen during production by polymerization to control the molecular weight and polymerization activity.

[0040] The intrinsic viscosity [η] can be determined by dissolving different amounts of the olefin resin composition in decalin at 135°C, determining the viscosity increase rate ηsp (i.e., ηsp / c) per unit concentration c of each polymer, and extrapolating ηred so that the unit concentration c of the polymer becomes zero.

[0041] The 4-methyl-1-pentene polymer (A4) preferably has a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (molecular weight distribution: Mw / Mn) measured by gel permeation chromatography (GPC) of 1.0 to 3.5, more preferably 1.2 to 3.0, and even more preferably 1.5 to 2.8. When the 4-methyl-1-pentene polymer (A4) has an Mw / Mn within the above range, deterioration in moldability due to a low molecular weight or low stereoregularity polymer is unlikely to occur, and molding is easy.

[0042] The 4-methyl-1-pentene polymer (A4) has a weight average molecular weight (Mw) of preferably 500 to 10,000,000, more preferably 1,000 to 5,000,000, and even more preferably 1,000 to 2,500,000, as measured by gel permeation chromatography (GPC) in terms of polystyrene.

[0043] The Mw / Mn and Mw of the 4-methyl-1-pentene polymer (A4) can be adjusted to the above ranges, for example, by using a metallocene catalyst. The Mw and Mw / Mn can be determined, for example, by analyzing a chromatogram obtained by measurement using a Waters ALC / GPC 150-C plus liquid chromatograph (integrated with a differential refractometer detector) with two GMH6-HT columns and two GMH6-HTL columns (manufactured by Tosoh Corporation) connected in series, o-dichlorobenzene as the mobile phase medium, at a flow rate of 1.0 ml / min and 140°C, using a calibration curve prepared using a standard polystyrene sample.

[0044] The density of the 4-methyl-1-pentene polymer (A4) (measured according to JIS K7112) is preferably 870 to 830 kg / m 3 , more preferably 865 to 830 kg / m 3 , more preferably 855 to 830 kg / m 3 The density can be appropriately changed by the comonomer composition ratio of the 4-methyl-1-pentene polymer (A4), and a polymer (A4) having a density within the above range is advantageous in producing a molded article.

[0045] When the olefin resin composition of the present invention contains the 4-methyl-1-pentene polymer (A4), a molded article obtained from the olefin resin composition can be suitably used for various applications without any restrictions. Such a molded article has excellent flexibility and good heat conductivity compared to a molded article containing the propylene polymer (A2), and therefore has properties such as being easily bendable when touched and easily retaining its shape at room temperature.

[0046] In the olefin resin composition of the present invention, the unmodified olefin polymer (A) is preferably one or more polymers selected from the group consisting of the above-mentioned (A1) to (A4), and more preferably the unmodified olefin polymer (A) comprises one or more of an ethylene polymer (A1) and a propylene polymer (A2). Furthermore, when the unmodified olefin polymer (A) comprises an ethylene polymer (A1) and a propylene polymer (A2), the resulting molded article has an excellent balance of mechanical properties, which is preferred. When the unmodified olefin polymer (A) comprises a propylene polymer (A2), the resulting molded article has excellent heat resistance, which is preferred.

[0047] The MFR (ASTM D1238, 230°C, 2.16 kg load) of the olefin polymer (A) is preferably 9 to 300 g / 10 min, more preferably 10 to 200 g / 10 min. The olefin polymer (A) having an MFR in the above range has good moldability such as injection moldability, and the obtained molded article also has good mechanical properties.

[0048] When the olefin polymer (A) is an ethylene polymer (A1), the MFR (ASTM D1238, 190°C, 2.16 kg load) is preferably 6 to 100 g / 10 min. Looking at the lower limit of the MFR, it is preferably 8 g / 10 min or more, more preferably 10 g / 10 min or more, and even more preferably 11 g / 10 min or more. Looking at the upper limit of the MFR, it is preferably 80 g / 10 min or less, more preferably 60 g / 10 min or less, and even more preferably 50 g / 10 min or less.

[0049] When the olefin polymer (A) is an ethylene polymer (A1), a propylene polymer (A2), or a 1-butene polymer (A3), the MFR (ASTM D1238, 230°C, 2.16 kg load) is preferably 20 to 150 g / 10 min, more preferably 30 to 100 g / 10 min, and further preferably 40 to 80 g / 10 min.

[0050] When the olefin polymer (A) is a 4-methyl-1-pentene polymer (A4), the upper limit of the MFR (ASTM D1238, 230°C, 2.16 kg load) is preferably 50 g / 10 min or less, more preferably 30 g / 10 min or less, further preferably 15 g / 10 min or less, and particularly preferably 13 g / 10 min or less.

[0051] <Acid-Modified Propylene Polymer (B)> The acid-modified propylene polymer (B), which is one of the components contained in the olefin resin composition of the present invention, improves the compatibility and adhesion between the unmodified olefin polymer (A) and the metal oxide (C). By improving the compatibility between them, the acid-modified propylene polymer (B) makes it easier to finely disperse the metal oxide (C), and can improve the processability, heat resistance, mechanical strength, and appearance of a molded article.

[0052] The acid-modified propylene polymer (B) can be obtained by modifying an unmodified propylene polymer by a known method.

[0053] The type of unmodified propylene polymer used as a raw material for the acid-modified propylene polymer is not particularly limited. The unmodified propylene polymer is a polymer containing 51 to 100 mol% of structural units derived from propylene, and examples thereof include propylene homopolymers and propylene-α-olefin copolymers. Specific examples of the α-olefin in the propylene-α-olefin copolymer include ethylene, 1-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradodecene, 1-hexadodecene, and 1-octadodecene. Specific preferred examples of the unmodified propylene polymer include propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, and propylene-ethylene random-1-butene copolymer, with propylene homopolymer being more preferred.

[0054] The unsaturated carboxylic acid used to modify the unmodified propylene polymer may be an unsaturated compound having one or more carboxylic acid groups (unsaturated carboxylic acid in the narrow sense), or a derivative of an unsaturated carboxylic acid, such as an ester of an unsaturated carboxylic acid with an alkyl alcohol or an unsaturated compound having a carboxylic anhydride such as an anhydride of an unsaturated carboxylic acid. The unsaturated group in these unsaturated carboxylic acids may be a vinyl group, a vinylene group, an unsaturated cyclic hydrocarbon group, or the like. Examples of unsaturated carboxylic acids in the narrow sense include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, nadic acid, and endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid. Examples of derivatives of unsaturated carboxylic acids include acid anhydrides such as maleic anhydride and citraconic anhydride, as well as acid halides, amidates, imides, and esters of (narrowly defined) unsaturated carboxylic acids such as malenyl chloride, malenylimide, monomethyl maleate, and dimethyl maleate. The unsaturated carboxylic acid is preferably maleic acid, nadic acid, or an acid anhydride thereof, and more preferably maleic anhydride. These unsaturated carboxylic acids may be used alone or in combination of two or more.

[0055] The monomers constituting the acid-modified propylene-based polymer (B) (propylene, other α-olefins other than propylene, unsaturated carboxylic acids) can be derived from any of fossil fuels, biomass, and chemically recycled materials. Furthermore, as the monomers constituting the acid-modified propylene-based polymer (B), raw materials derived from fossil fuels and biomass may be used in combination, raw materials derived from fossil fuels and chemically recycled materials may be used in combination, raw materials derived from biomass and chemically recycled materials may be used in combination, or raw materials derived from fossil fuels, biomass, and chemically recycled materials may be used in combination.

[0056] When the unmodified propylene polymer is modified with the unsaturated carboxylic acid, an organic peroxide is usually used as a radical initiator. Examples of the organic peroxide include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-amyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, t-amyl peroxypivalate, t-hexylperoxy-2-ethylhexanoate, t-butyl peroxypivalate, t-hexyl per ...butyl peroxypivalate, t-amyl peroxypivalate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, t-hexyl peroxy-2-ethylhexano -butylperoxy-2-ethylhexanoate, t-amylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, 1,1-di(t-butylperoxy)-2-methylcyclohexane, 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 1,1-di(t-amylperoxy)cyclohexane, 2,2-di(4,4-di-(t-butylperoxy)cyclohexane) (-oxy)cyclohexyl)propane, t-amylperoxyisononanoate, t-hexylperoxyisopropyl monocarbonate, t-amylperoxynormal octoate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-amylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-amylperoxy-2-ethylhexyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, t-butyl peroxyacetate, t-amyl peroxyacetate, 2,2-di-(t-butylperoxy)butane, t-butyl peroxyisononanoate, t-amyl peroxybenzoate, t-butyl peroxybenzoate, n-butyl-4,4-di-(t-butylperoxy)valerate, methyl ethyl ketone peroxide, di(2-t-butylperoxyisopropyl)benzene, ethyl-3,3-di(t-butylperoxy)butyrate, di-t-hexyl peroxide, 1,3-di(2-t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-amyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3, t-amyl hydroperoxide, t-butyl hydroperoxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, and 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane. Of these, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, di-t-butyl peroxide, t-butylperoxyisopropyl monocarbonate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3, dicumyl peroxide, and t-butyl peroxybenzoate are preferred. These organic peroxide acids may be used alone or in combination of two or more.

[0057] The amount of the organic peroxide used during modification can be from 0.01 to 30 parts by mass, preferably from 1 to 20 parts by mass, and more preferably from 2 to 15 parts by mass, relative to 100 parts by mass of the unmodified propylene-based polymer.

[0058] The amount of unsaturated carboxylic acid contained in the acid-modified propylene polymer (B) is preferably 0.005% by mass or more and 10% by mass or less, more preferably 0.01% by mass or more and 5% by mass or less, and even more preferably 0.02% by mass or more and 3% by mass or less, based on the total mass of the acid-modified propylene polymer (B).

[0059] The amount of unsaturated carboxylic acid in the olefin resin composition of the present invention is preferably 0.002 to 0.42 parts by mass, more preferably 0.005 to 0.35 parts by mass, and even more preferably 0.01 to 0.1 parts by mass, per 100 parts by mass of the total of the unmodified olefin polymer (A), the acid-modified propylene polymer (B), the metal oxide (C), and the unmodified polyolefin wax (D). Here, the amount of unsaturated carboxylic acid generally refers to the amount of unsaturated carboxylic acid contained in the acid-modified propylene polymer (B). That is, the olefin resin composition of the present invention preferably contains the acid-modified propylene polymer (B) in an amount containing the unsaturated carboxylic acid as described above. When the content of unsaturated carboxylic acid in the olefin resin composition of the present invention is within the above range, compatibility and adhesion between the unmodified olefin polymer (A) and the metal oxide (C) in the resin composition are improved, and molded articles having excellent texture and strength can be easily obtained from the resin composition, which is preferable.

[0060] The density of the acid-modified propylene polymer (B) (measured according to JIS K7112) is preferably 860 to 930 kg / m 3 and more preferably 880 to 925 kg / m 3 and more preferably 890 to 920 kg / m 3 is.

[0061] The number-average molecular weight (Mn) of the acid-modified propylene polymer (B), measured by gel permeation chromatography (GPC), is preferably 2,000 to 60,000, more preferably 7,000 to 50,000, and even more preferably 10,000 to 45,000, in terms of polystyrene. The acid-modified propylene polymer (B) having a number-average molecular weight (Mn) within the above range can effectively improve the dispersibility of the metal oxide (C) in the resin composition, and can further improve the appearance, heat resistance, and mechanical strength of the molded article. Furthermore, the processability and kneadability of the resin composition are also improved.

[0062] <Metal Oxide (C)> The metal oxide (C), one of the components contained in the olefin resin composition of the present invention, is not particularly limited in type as long as it is a metal oxide, but it may be a metal oxide having a higher thermal conductivity than the olefin polymer (A). For example, metal oxides such as magnesium oxide (45 to 60 W / mK), aluminum oxide (17 to 36.0 W / mK), zinc oxide (25 to 54 W / mK), and titanium oxide (8.4 W / mK) can be used. Two or more metal oxides may be used in combination. The numerical value in parentheses after the substance name indicates the thermal conductivity at 300 K.

[0063] The metal oxide (C) according to the present invention is preferably a metal oxide having a thermal conductivity in the range of 10 to 300 W / mK. The lower limit of the thermal conductivity is more preferably 15 W / mK, even more preferably 20 W / mK, particularly preferably 30 W / mK, and most preferably 40 W / mK.

[0064] The upper limit of the thermal conductivity is more preferably 250 W / mK, even more preferably 200 W / mK, and particularly preferably 100 W / mK. By using the metal oxide (C) having a thermal conductivity within the above range, the olefin resin composition obtained by mixing the metal oxide (C) with the unmodified olefin polymer (A) or the acid-modified propylene polymer (B) has an appropriate thermal conductivity, and therefore, a molded article such as a container can be obtained that feels cool to the touch and feels warm when hot food is placed inside.

[0065] Unlike the case where titanium oxide is used as a photocatalyst, the metal oxide (C) is preferably magnesium oxide or zinc oxide in applications that do not require light irradiation and require antibacterial and / or antiviral properties, and more preferably magnesium oxide because it is white in color, easy to color, and inexpensive.

[0066] The metal oxide (C) according to the present invention may have a spherical, cubic, plate-like, columnar, hexagonal plate-like shape, etc., of which the spherical shape is preferred. The metal oxide (C) may also be pulverized.

[0067] The metal oxide (C) according to the present invention preferably has an average particle size in the range of 0.1 to 110 μm. The lower limit of the average particle size is more preferably 0.5 μm, even more preferably 1 μm, and particularly preferably 3 μm. The particle size (average particle size) of the metal oxide (C) is the 50% particle size (d50) obtained from the cumulative % distribution curve measured with a laser diffraction particle size distribution analyzer.

[0068] The upper limit of the average particle size is more preferably 80 μm, even more preferably 70 μm, and particularly preferably 60 μm. If the average particle size is too small, the particles may be easily aggregated, which may result in poor handling and difficulty in uniformly mixing with the olefin polymer (A). On the other hand, if the average particle size is too large, the thermal conductivity of the resulting olefin resin composition may be too low, and the mechanical properties of the resulting molded article may be deteriorated.

[0069] The use of a metal oxide (c1) having a small average particle size as the metal oxide (C) is more preferable in terms of the mechanical properties of the resulting resin composition and molded article. The average particle size of the metal oxide (c1) is 0.1 μm or more and less than 10 μm, preferably 0.5 μm or more and less than 10 μm, more preferably 1 μm or more and less than 10 μm, and even more preferably 3 μm or more and less than 10 μm. The metal oxide (c1) is preferably a metal oxide pulverized to the above average particle size.

[0070] The use of a metal oxide (c2) having a large average particle size as the metal oxide (C) is more preferable in terms of the fluidity and moldability of the resulting resin composition. The average particle size of the metal oxide (c2) is 10 μm or more and 110 μm or less, preferably 10 μm or more and 80 μm or less, more preferably 10 μm or more and 70 μm or less, and even more preferably 10 μm or more and 60 μm or less. The metal oxide (c2) is preferably a spherical metal oxide.

[0071] In applications requiring higher thermal conductivity, it is preferable to use a metal oxide (c1) having an average particle size of 0.1 μm or more but less than 10 μm and a metal oxide (c2) having an average particle size of 10 μm or more but less than 110 μm in combination. In this case, the blending ratio (mass ratio) of (c1) / (c2) is preferably 1 / 99 to 49 / 51, more preferably 5 / 95 to 45 / 55, and even more preferably 10 / 90 to 40 / 60.

[0072] By using a metal oxide (c1) having a small average particle size in combination with a metal oxide (c2) having a large average particle size, the metal oxide (c1) fills the gaps between the metal oxides (c2), increasing the packing density, and thereby improving the thermal conductivity of the resulting olefin-based resin composition.

[0073] Furthermore, from the viewpoint of uniformity of heat conduction, etc., it is preferable that the metal oxide (C) has a small aspect ratio. Specifically, the aspect ratio is preferably less than 1.2, more preferably less than 1.1.

[0074] The metal oxide (C) according to the present invention is preferably water-resistant. Preferably, the metal oxide (C) is substantially free of metal hydroxides and hydrates thereof, and metal oxide hydrates. Specifically, the content of metal hydroxides and hydrates thereof, and metal oxide hydrates in 100% by mass of the entire metal oxide (C) is preferably 1% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.3% by mass or less.

[0075] <Unmodified Polyolefin Wax (D)> The unmodified polyolefin wax (D), which is one of the components contained in the olefin resin composition of the present invention, is a low-molecular-weight polymer and is not particularly limited as long as it is an unmodified wax made of a polyolefin such as polyethylene wax or polypropylene wax, but polyethylene wax and polypropylene wax are preferred, and polyethylene wax is more preferred.

[0076] The unmodified polyolefin wax (D) according to the present invention is unmodified and has not been modified by oxidation or with an unsaturated carboxylic acid or the like. The unmodified polyolefin wax (D) according to the present invention preferably has an acid value of 0.01 mgKOH / g or less, more preferably 0 mgKOH / g, as measured in accordance with JIS K0070. The monomers constituting the unmodified polyolefin wax (D) can be derived from fossil fuels, biomass, or chemically recycled. The raw material monomers for the unmodified polyolefin wax (D) may be a combination of fossil fuel-derived and biomass-derived raw materials, a combination of fossil fuel-derived and chemically recycled raw materials, a combination of biomass-derived and chemically recycled raw materials, or a combination of fossil fuel-derived, biomass-derived, and chemically recycled raw materials.

[0077] <Polyethylene Wax> The polyethylene wax used as the unmodified polyolefin wax (D) according to the present invention is a wax comprising an ethylene homopolymer or a copolymer of ethylene and an α-olefin. As the α-olefin, an α-olefin having 3 to 10 carbon atoms is preferred, an α-olefin having 3 to 8 carbon atoms is more preferred, and 1-butene is even more preferred. Examples of the polyethylene wax include polymers or copolymers containing ethylene-derived structural units as the main component (ethylene: 51 to 100 mol % content).

[0078] The polyethylene wax according to the present invention preferably has a density of 890 to 980 kg / m as measured in accordance with the density gradient tube method of JIS K7112 (1999). 3 More preferably, it is in the range of 895 to 975 kg / m 3 When the density of the polyethylene wax falls within this range, the dispersibility of the polyethylene wax in the olefin resin composition is improved.

[0079] The polyethylene wax according to the present invention preferably has a number average molecular weight (Mn) of 700 to 4,000, more preferably 1,500 to 3,800, calculated as standard polyethylene, as measured by gel permeation chromatography.

[0080] A polyethylene wax having a number-average molecular weight (Mn) of 700 to 4,000 can be appropriately dispersed in the unmodified olefin polymer (A) when preparing the olefin resin composition of the present invention, and also contributes to the dispersibility of the metal oxide (C). It can also reduce the extrusion load during molding and extrusion. As a result, the productivity of molded products can be further improved.

[0081] The polyethylene wax according to the present invention preferably has a weight average molecular weight (Mw) of 1,000 to 9,000, more preferably 1,500 to 8,000, and even more preferably 2,000 to 7,000, as converted into standard polyethylene, as measured by gel permeation chromatography.

[0082] The polyethylene wax according to the present invention preferably has a melting point of 70 to 130° C., more preferably 80 to 129° C. The melting point of the polyethylene wax was measured by a differential scanning calorimeter (DSC) in accordance with JIS K7121.

[0083] <Polypropylene Wax> The polypropylene wax used as the unmodified polyolefin wax (D) according to the present invention is a wax comprising a propylene homopolymer, or a copolymer of propylene with ethylene or an α-olefin. As the α-olefin, an α-olefin having 4 to 10 carbon atoms is preferred, an α-olefin having 4 to 8 carbon atoms is more preferred, and 1-butene is even more preferred. Examples of the polypropylene wax include polymers or copolymers containing propylene-derived structural units as the main component (propylene: content: 51 to 100 mol %).

[0084] The density, number average molecular weight (Mn), weight average molecular weight (Mw), and melting point (Tm) of the polypropylene wax according to the present invention are not particularly limited, but it is desirable that they are each in the same range as the preferred properties of the polyethylene wax described above.

[0085] <Olefin Resin Composition> The olefin resin composition of the present invention is a composition comprising 9.7 to 36 parts by mass of the unmodified olefin polymer (A), 0.3 to 15 parts by mass of the acid-modified propylene polymer (B), 54 to 90 parts by mass of the metal oxide (C) (where the total amount of the unmodified olefin polymer (A), the acid-modified propylene polymer (B), and the metal oxide (C) (the total of (A) + (B) + (C)) is defined as 100 parts by mass), and 0.1 to 10 parts by mass of the unmodified polyolefin wax (D) relative to 100 parts by mass of the total of (A) + (B) + (C).

[0086] In the olefin resin composition of the present invention, when the total amount of (A) + (B) + (C) is taken as 100 parts by mass, the lower limit of the content of the unmodified olefin polymer (A) is preferably 11.5 parts by mass, more preferably 13.3 parts by mass, even more preferably 15.1 parts by mass, and even more preferably 21.1 parts by mass. When the content of the olefin polymer (A) in the olefin resin composition is a certain amount or more, existing molding methods such as injection molding can be used.

[0087] The upper limit of the content of the unmodified olefin polymer (A) is preferably 35 parts by mass, more preferably 33 parts by mass, even more preferably 32 parts by mass, and particularly preferably 26 parts by mass. When the content of the unmodified olefin polymer (A) in the olefin resin composition of the present invention is a certain amount or less, the thermal conductivity of the resulting olefin resin composition is sufficiently exhibited, and the resulting molded article has a sense of weight and texture.

[0088] In the olefin resin composition of the present invention, when the total amount of (A) + (B) + (C) is taken as 100 parts by mass, the lower limit of the content of the acid-modified propylene polymer (B) is preferably 0.3 parts by mass, more preferably 0.5 parts by mass, even more preferably 0.7 parts by mass, and even more preferably 0.9 parts by mass. When the content of the acid-modified propylene polymer (B) in the olefin resin composition is a certain amount or more, the dispersibility of the metal oxide (C) in the resin composition can be improved, and the appearance, heat resistance, surface hardness, and mechanical strength of the molded product can be improved.

[0089] The upper limit of the content of the acid-modified propylene polymer (B) is 15 parts by mass, preferably 12 parts by mass, more preferably 10 parts by mass, even more preferably 8 parts by mass, still more preferably 7 parts by mass, and particularly preferably 5 parts by mass. When the content of the acid-modified propylene polymer (B) in the thermoplastic resin composition / olefin resin composition of the present invention is a certain amount or less, the dispersibility of the metal oxide (C) in the resin composition can be improved, the appearance, heat resistance, surface hardness, and mechanical strength of the molded product can be improved, and the processability and kneadability of the resin composition can also be improved.

[0090] In the olefin resin composition of the present invention, when the total amount of (A) + (B) + (C) + (D) is taken as 100 parts by mass, the content of the acid-modified propylene polymer (B) is preferably such that the amount of unsaturated carboxylic acid contained in the acid-modified propylene polymer (B) satisfies the range of preferably 0.002 to 0.42 parts by mass, more preferably 0.005 to 0.35 parts by mass, and even more preferably 0.01 to 0.1 parts by mass. When the unsaturated carboxylic acid content is within the above range, the compatibility and adhesion between the unmodified olefin polymer (A) and the metal oxide (C) in the olefin resin composition of the present invention are improved, and a molded article having excellent texture and strength can be easily obtained from the resin composition, which is preferable.

[0091] On the other hand, when the total amount of (A) + (B) + (C) is taken as 100 parts by mass, the lower limit of the content of the metal oxide (C) is preferably 57 parts by mass, more preferably 60 parts by mass, even more preferably 63 parts by mass, and even more preferably 69 parts by mass. The upper limit of the content of the metal oxide (C) is preferably 88 parts by mass, more preferably 86 parts by mass, even more preferably 84 parts by mass, and even more preferably 78 parts by mass.

[0092] The olefin resin composition of the present invention contains 0.1 to 10 parts by mass of unmodified polyolefin wax (D) per 100 parts by mass of the total of the unmodified olefin polymer (A), the acid-modified propylene polymer (B), and the metal oxide (C) (total of (A) + (B) + (C)). The lower limit of the content of the unmodified polyolefin wax (D) is preferably 0.2 parts by mass, more preferably 0.4 parts by mass, and even more preferably 0.5 parts by mass.

[0093] The upper limit of the content of the unmodified polyolefin wax (D) is preferably 8 parts by mass, more preferably 6 parts by mass, and even more preferably 4 parts by mass. By containing the unmodified polyolefin wax (D) in the above range, the olefin resin composition of the present invention can improve kneadability by reducing the molding torque when obtaining the olefin resin composition and when molding the olefin resin composition. Furthermore, since the melting temperature is lower than that of the olefin polymer (A), it acts as a lubricant and can prevent wear of the screw and cylinder.

[0094] On the other hand, since the olefin resin composition of the present invention does not contain a modified polyolefin wax, there is no risk of generating an unpleasant odor during molding. Furthermore, a molded article obtained from the olefin resin composition of the present invention containing the unmodified polyolefin wax (D) has a harder texture and a texture closer to that of pottery than a molded article obtained from a composition containing a modified polyolefin wax, and there is no change in hydrophilicity, so there is no risk of metal oxide elution or deterioration in texture.

[0095] The olefin resin composition of the present invention preferably has a specific gravity in the range of 1.2 to 5.0. The olefin resin composition of the present invention more preferably has a lower limit of specific gravity of 1.4, even more preferably 1.6, and particularly preferably 1.7. The upper limit of specific gravity is more preferably 4.0, even more preferably 3.0, and particularly preferably 2.5. By having the specific gravity satisfy the above range, a molded product with a better texture can be obtained.

[0096] The olefin resin composition of the present invention preferably has a thermal conductivity in the range of 0.5 to 5 W / mK. The olefin resin composition of the present invention preferably has a lower limit of thermal conductivity of 0.6 W / mK, more preferably 0.65 W / mK, and particularly preferably 0.7 W / mK. The upper limit of thermal conductivity is more preferably 4.5 W / mK, even more preferably 4.0 W / mK, and particularly preferably 3.6 W / mK. When the thermal conductivity satisfies the above range, a cool feeling can be felt when touched, and molded articles such as containers with a better texture can be obtained.

[0097] The olefin resin composition of the present invention preferably has an antibacterial activity value (water resistance category 0 and light resistance category 0) of 2.0 or more using Escherichia coli or Staphylococcus aureus, more preferably 2.0 or more using Escherichia coli and Staphylococcus aureus. The antibacterial activity value of the olefin resin composition of the present invention can be increased, for example, by increasing the content of metal oxide (C) (e.g., magnesium oxide). An antibacterial activity value of 2.0 or more is considered to be antibacterial. A higher antibacterial activity value (water resistance category 0 and light resistance category 0) indicates a higher antibacterial effect, and is therefore preferred, with no particular upper limit. The antibacterial activity value (water resistance category 0 and light resistance category 0) in the present invention is an index value based on the test method in JIS Z 2801:2012 "Film Adhesion Method." Water resistance category 0 is category 0 (conditions without water resistance pretreatment) in the "Antibacterial Product Technology Council Test Method, Durability Test Method (2021 Edition) (1) Water Resistance Test." In addition, light resistance category 0 is category 0 (conditions under which no light resistance pretreatment is performed) in the "Antibacterial Product Technology Council Test Method: Durability Test Method (2021 Edition) (2) Light Resistance Test."

[0098] The olefin resin composition of the present invention preferably has an antiviral activity value of 2.0 or more using feline calicivirus. An antiviral activity value of 2.0 or more is considered to have an antiviral effect. A larger antiviral activity value indicates a higher antiviral effect, and is therefore preferred, with no particular upper limit. The antiviral activity value in the present invention is an index value based on the test method in ISO 21702:2019 "Determination of antiviral activity of plastics and other non-porous surfaces."

[0099] The olefin resin composition of the present invention may contain various known additives depending on the application, such as plasticizers, lubricants, antioxidants, ultraviolet absorbers, heat stabilizers, pigments, pigment masterbatches, dyes, antistatic agents, flame retardants, coupling agents, and dispersants, within the scope of not impairing the object of the present invention.

[0100] <Method of manufacturing olefin-based resin composition> The olefin-based resin composition of the present invention is obtained by mixing the above-mentioned components using a dry blend, a Henschel mixer, a Banbury mixer, a kneader, or the like, or by mixing and then melt-kneading the components using a single-screw extruder, a twin-screw extruder, a high-speed twin-screw extruder, or the like.

[0101] <Molded Articles> The olefin resin composition of the present invention has excellent moldability and can be used in various molding methods. Specific examples of molded articles obtained from the olefin resin composition of the present invention include injection molded articles, foam molded articles, injection foam molded articles, extrusion molded articles, blow molded articles, vacuum / pressure molded articles, calendar molded articles, three-dimensional laminated articles, microwave molded articles, stretched films, inflation films, etc.

[0102] More specifically, examples include containers for food, tableware such as forks, knives, spoons, plates, teapots, and teacups, sake bottles (sake bottles) and choshi (sake cups), and cutlery rests such as chopstick rests. These products are highly useful as alternatives to ceramic tableware, sake vessels, containers, and cutlery, as they can be easily molded by injection molding, allow for a sense of warmth and coldness of the contents, and provide a sense of weight. They can also be used for other applications, such as everyday items like lampshades and vases, housings and structural materials for certain audio speakers (such as high-end speakers), plumbing products like sinks and toilets, and vases and pots for plants. Taking advantage of their ability to impart a sense of weight and stability, ceramics can also be used for other applications, such as model and toy applications, including plastic models, furniture applications like desks and chairs, home appliances like refrigerators, rice cookers, and vacuum cleaners, musical instruments like piano keyboards, architectural applications like tiles and artificial marble substitutes, and building materials, and clothing applications like buttons. Furthermore, by taking advantage of its warm and cool sensation and moldability, it may also be suitable as a filament for 3D printers.

[0103] Other examples of the molded article of the present invention include containers such as various bottles and jars that take advantage of features such as designability, stability, antibacterial properties, and tactile feel, steering wheels and shift knobs for vehicles and ships, door handles and doorknobs, various switches, handrails, mice, keyboards, controllers, remote controls, decorative accessories, stationery (such as mechanical pencils, ballpoint pens, and fountain pens), smartphone covers, tablet covers, housings for personal computers, tablets, and smartphones, housings for various home appliances, housings for beauty appliances, housings for household appliances, electricity storage devices (such as battery cases), book covers, wallpaper, wall materials, floor materials, building materials, toilets, and toilet supplies, and these can be suitably used in places that are touched by hands on a daily basis.

[0104] Suitable examples of containers include those for beauty-related products such as cosmetics (lotion liquid, cosmetic cream, etc.), shampoo (including body shampoo), conditioner, etc., where these performances tend to have a significant impact on the commercial value. More specifically, examples include containers with lids (including airless containers), (cosmetic) compacts, (cosmetic) palettes, bottles, etc.

[0105] In recent years, plastic containers such as polyolefins, which are lightweight and have excellent impact resistance, have been used in most cases for such applications, but these materials are not suitable for creating a luxurious feel in terms of sight, touch (including thermal conductivity, weight, etc.), etc. Containers such as ceramics are suitable for creating a luxurious feel, but these have major problems such as limited freedom in terms of design and mass production, and low impact resistance.

[0106] The container of the present invention can be molded using the same molding methods as conventional plastic products, and therefore not only has excellent productivity and design, but also has superior impact resistance compared to ceramics, and has the same weight and thermal conductivity as ceramics, making it suitable for the above-mentioned uses.

[0107] Furthermore, molded articles obtained from the olefin-based resin composition of the present invention are also useful as heat-dissipating components in applications requiring high thermal conductivity. For example, they are extremely useful as heat-dissipating components, such as heat-dissipating sheets for electronic components requiring high thermal conductivity, and for various electronic devices such as laptop computers and mobile devices. Furthermore, by applying the olefin-based resin composition of the present invention to part or all of the housing of various electronic devices such as laptop computers and mobile devices and using it in combination with a heat-dissipating sheet, it is expected that the heat-dissipating performance of the electronic device will be further improved. Furthermore, it is also possible to manufacture a housing that reduces the risk of low-temperature burns during prolonged operation by using the olefin-based resin composition of the present invention in part of the housing of various electronic devices such as laptop computers and mobile devices, and using materials with reduced metal oxide content or metal oxide-free materials in other parts, such as areas that are frequently touched by hands during operation. Such a housing can be manufactured, for example, by installing multiple resin injection gates in a mold for molding the housing and injecting resins of different compositions into each gate.

[0108] Other applications include its excellent thermal conductivity, flexibility in shape during molding, and high impact strength, making it useful as a substitute for metal housings. For example, it can be expected to be used in housings and straps for watches and clocks, furniture parts (such as metal handles), and exterior materials for home appliances such as washing machines and refrigerators.

[0109] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. The materials used in the examples are as follows. The methods for evaluating each physical property will be described later.

[0110] (1) Unmodified Olefin Polymer (A) The olefin polymer (A) used in the examples and comparative examples is shown below. (1-1) Propylene polymer (A2-1): Propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., trade name J-6083HP, MFR (230°C, load 2.16 kg) = 60 g / 10 min, density = 900 kg / m 3(1-2) Ethylene-based polymer (A1-1): Ethylene-1-butene copolymer (manufactured by Mitsui Chemicals, Inc., Tafmer (registered trademark) product name A-35070S, MFR (190°C, load 2.16 kg) = 35 g / 10 min, MFR (230°C, load 2.16 kg) = 65 g / 10 min, density = 870 kg / m 3 )

[0111] (2) Acid-Modified Propylene Polymer (B) The acid-modified propylene polymer (B) used in the examples and comparative examples was produced by the method described below.

[0112] (2-1) Acid-Modified Propylene Polymer (B-1) 100 parts by mass of polypropylene (Prime Polypro (trade name) Grade E-200 GP, manufactured by Prime Polymer Co., Ltd.) was mixed with 1 part by mass of maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.25 parts by mass of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3 (trade name Perhexyne 25B, manufactured by NOF Corporation), and the mixture was extruded using a twin-screw kneader (manufactured by The Japan Steel Works, Ltd., TEX-30, L / D = 40, vacuum vent used) at a cylinder temperature of 220°C, a screw rotation speed of 200 rpm, and a discharge rate of 80 g / min to obtain an acid-modified propylene polymer (B-1) containing maleic acid-modified polypropylene and unreacted maleic anhydride. The resulting polymer (B-1) was dissolved in xylene, reprecipitated in acetone, and purified. The graft amount of maleic anhydride was measured by IR and found to be 0.7% by mass. The number average molecular weight (Mn) was measured by GPC and found to be 28,000. The density was 910 kg / m 3 It was.

[0113] (2-2) Acid-modified propylene polymer (B-2) 100 parts by mass of polypropylene (Prime Polypro (trade name) Grade J106G, manufactured by Prime Polymer Co., Ltd.) was mixed with 15 parts by mass of maleic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) and 2.5 parts by mass of dicumyl peroxide (manufactured by NOF Corporation, trade name Percumyl D), and the mixture was allowed to react in a toluene solution for 5 hours to obtain an acid-modified propylene polymer (B-2) containing maleic acid-modified polypropylene and unreacted maleic anhydride. The obtained polymer (B-2) was dissolved in xylene and purified by reprecipitation in acetone. The graft amount of maleic anhydride was measured by IR and found to be 2.8% by mass. The number average molecular weight (Mn) was measured by GPC and found to be 18,000. The density was 910 kg / m 3 It was.

[0114] (3) Metal Oxides (C) The metal oxides (C) used in the examples and comparative examples are as follows: (3-1) Magnesium oxide (C1-1): MgO (Kyowa Chemical Industry Co., Ltd., Pyroxma 3320, average particle size = 20 μm) (3-2) Magnesium oxide (C1-2): MgO (Ube Material Industries, Ltd., RF-10CS, average particle size = 5.0 μm) (3-3) Aluminum oxide (C2-1): Alumina (Denka Co., Ltd., Denka spherical alumina DAM-45, average particle size = 42.8 μm)

[0115] (4) Unmodified Polyolefin Wax (D) The unmodified polyolefin wax (D) used in the examples and comparative examples is shown below. (4-1) Unmodified Polyolefin Wax (D-1): Ethylene-1-butene copolymer (manufactured by Mitsui Chemicals, Inc., trade name EXCEREX 30050B, density = 907 kg / m 3 , acid value = 0 mg KOH / g, melting point = 91 ° C, weight average molecular weight = 5100, molecular weight distribution Mw / Mn = 2.6)

[0116] (5) Modified Polyolefin Wax (5-1) Modified Polyolefin Wax: Modified polyolefin polymer (manufactured by Mitsui Chemicals, Inc., trade name Excelex 15341PA, density = 930 kg / m 3 , acid value = 14 mg KOH / g, melting point = 89 ° C.

[0117] The physical properties of the olefin resin compositions obtained in the examples and comparative examples were measured by the following methods. The specific gravity and melt flow rate (MFR) were measured using resin composition pellets, and the other physical properties were measured using property test samples.

[0118] [Specific Gravity] The specific gravity was measured by the underwater displacement method in comparison with the density of water at 4° C. [Melt Flow Rate (MFR) (g / 10 min)] Measured in accordance with ASTM D1238 using an AUTO MELTS INDEXER TP-407 manufactured by Tester Sangyo Co., Ltd. under conditions of a temperature of 230° C. and a load of 2.16 kg and a temperature of 230° C. and a load of 5 kg.

[0119] [Tensile strength, tensile elongation at break] Measurements were made in accordance with JIS K6251 using a Strograph VG1F manufactured by Toyo Seiki Seisaku-sho, Ltd., using a sample shape of JIS No. 3, under the conditions of a test speed of 500 mm / min, a grip distance of 55 mm, a gauge length of 20 mm, and a test temperature of 23° C. For the measurement of tensile elongation at break, a gauge tracing device was attached to the test piece during the tensile strength measurement, and the elongation at break was measured.

[0120] [IZOD impact strength] In accordance with ASTM D256, a digital impact tester DG-IB manufactured by Toyo Seiki Seisakusho Co., Ltd. was used to measure a test piece (63 mm x 13 mm x 2 mm thick, notched) under the conditions of a hammer capacity of 3.92 J, an idling angle of 148.9°, and a test temperature of 23°C. [Rockwell hardness] In accordance with JIS K7202-2 (ISO2039-2), a Mitutoyo Corporation automatic Rockwell hardness tester HR-523 was used to measure a test piece (three stacked 2 mm press sheets) under the conditions of a scale of HRR, a test pressure of 588.4 N, and a test temperature of 23°C.

[0121] [Charpy Impact] In accordance with JIS K7111-1, a digital impact tester DG-UB manufactured by Toyo Seiki Seisakusho Co., Ltd. was used to measure a test piece (80 mm x 10 mm x 2 mm thick, notched) under the conditions of a hammer capacity of 2 J, an idling angle of 148.9°, and a test temperature of 23°C.

[0122] [Flexural Strength, Flexural Stress, and Flexural Modulus] In accordance with ASTM D790, a Shimadzu Corporation 5-section bending tester AG-1kNX plus was used to measure the flexural strength, flexural stress, and flexural modulus of elasticity using test pieces (65 mm × 14 mm × 2 mm thick) under the following conditions: a support distance (span distance: 16 times the thickness) of 32 mm, a test speed of 5 mm / min, and a test temperature of 23°C.

[0123] [Pencil hardness] Measured in accordance with JIS K5600-56 using a pencil scratch hardness tester SH-V manufactured by Toyo Seiki Seisakusho Co., Ltd. under a load of 750 g. [Linear expansion coefficient] Measured in accordance with JIS K 7197 using a TMA-SS7100 manufactured by SII Nanotechnology Inc. under the conditions of a TMA method (without annealing) in a compression expansion mode, a measurement temperature range of 23°C to 60°C, a test load of 26 mN, and a heating rate of 5°C / min.

[0124] [Head deflection temperature measurement (°C)] In accordance with ISO 75-2 Method A, a fully automatic HDT tester, Model 6A-2, manufactured by Toyo Seiki Co., Ltd., was used. Test specimens (80 mm x 10 mm x 2 mm thick) were used. Measurements were performed under the following conditions: a heating rate of 120°C / hour, a test start temperature of 35°C, and a bending stress of 1.80 MPa. [Thermal conductivity (W / m K)] In accordance with ASTM E1530, a steady-state thermal conductivity measuring device, Model GH-1, manufactured by ULVAC-RIKO, Inc., was used. Measurements were performed using specimens (50 mm diameter x 2 mm thick) at a sample holding air pressure of 0.3 MPa and a set temperature of 30°C. [Water absorption (wt%)] Water absorption measurements were performed at 23°C for 24 hours.

[0125] Examples 1 to 3 Propylene polymer (A2-1), ethylene polymer (A1-1), acid-modified propylene polymer (B-1), magnesium oxide (C1-1), and unmodified polyolefin wax (D-1) were introduced as raw materials into a kneading device (a benchtop kneader manufactured by Irie Shokai) so as to obtain the formulations shown in Table 1, and kneaded at 200°C and 15 to 35 rpm to obtain pellets of a thermoplastic resin composition. The obtained pellets of the thermoplastic resin composition were pressed into a sheet of a predetermined thickness at 200°C using a manual hydraulic heating press (manufactured by Imoto Machinery Works, Ltd.), and the pressed sheet was cut into a predetermined shape to obtain a sample for physical property testing. The obtained sheet was used to measure the various physical properties using the methods described above. The results are shown in Table 1.

[0126] Examples 4 to 6 Pellets and test samples of thermoplastic resin compositions were produced in the same manner as in Example 1, except that raw materials, propylene polymer (A2-1), ethylene polymer (A1-1), acid-modified propylene polymer (B-2), magnesium oxide (C1-1), and unmodified polyolefin wax (D-1), were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai) in the proportions shown in Table 1. The physical properties were measured by the methods described above. The results are shown in Table 1.

[0127] Comparative Example 1 Pellets of a thermoplastic resin composition and a test sample were produced in the same manner as in Example 1, except that 68 parts by mass of a propylene polymer (A2-1), 2.0 parts by mass of an ethylene polymer (A1-1), 30 parts by mass of magnesium oxide (C-1), and 0.6 parts by mass of an unmodified polyolefin wax (D-1) were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai Co., Ltd.), and the physical properties were measured by the methods described above. The results are shown in Table 1. The composition obtained in Comparative Example 1 had low thermal conductivity and was poor at conducting heat, and therefore did not achieve a ceramic-like texture or a luxurious feel. Furthermore, because the content of the metal oxide (C) was low, the surface hardness and deflection temperature under load (1.80 MPa) were significantly reduced, making the composition difficult to use on a daily basis.

[0128] Comparative Example 2 Pellets and test samples of a thermoplastic resin composition were produced in the same manner as in Example 1, except that 23 parts by mass of a propylene polymer (A2-1), 2.0 parts by mass of an ethylene polymer (A1-1), 75 parts by mass of magnesium oxide (C-1), and 0.6 parts by mass of a modified polyolefin wax were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai Co., Ltd.) as raw materials, and the physical properties were measured by the methods described above. The results are shown in Table 1. The composition obtained in Comparative Example 2 had a lower deflection temperature under load and thus lower physical properties. This is thought to be because the modified polyolefin wax had a low acid value, which resulted in weak hydrogen bonding with the metal oxide (hereinafter also referred to as filler), and the filler did not disperse uniformly in the resin. On the other hand, since the unmodified polyolefin wax (D) used in the examples has an acid value of 0, the hydrogen bond with the filler is weak, but the interaction with the small amount of acid-modified propylene polymer (B) acting as a binder is strong, which is thought to be why the deflection temperature under load and physical properties of the resulting composition were good.

[0129] Comparative Example 3 Pellets of a thermoplastic resin composition and a test sample were produced in the same manner as in Example 1, except that 23 parts by mass of a propylene polymer (A2-1), 2.0 parts by mass of an ethylene polymer (A1-1), and 75 parts by mass of magnesium oxide (C-1) were introduced as raw materials into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai Co., Ltd.), and the physical properties were measured by the methods described above. The results are shown in Table 1. The composition obtained in Comparative Example 3 did not contain the acid-modified propylene polymer (B) and the unmodified polyolefin wax (D). This made the filler prone to agglomeration and difficult to uniformly disperse, making production difficult and prone to unevenness, resulting in poor kneadability and resin fluidity (MFR).

[0130] Example 7 Pellets and test samples of a thermoplastic resin composition were produced in the same manner as in Example 1, except that raw materials, propylene polymer (A2-1), ethylene polymer (A1-1), acid-modified propylene polymer (B-1), aluminum oxide (C2-1), and unmodified polyolefin wax (D-1), were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai) in the proportions shown in Table 1. The physical properties were measured by the methods described above. The results are shown in Table 1.

[0131] [Example 8] Pellets and test samples of a thermoplastic resin composition were produced in the same manner as in Example 1, except that raw materials, propylene polymer (A2-1), ethylene polymer (A1-1), acid-modified propylene polymer (B-2), aluminum oxide (C2-1), and unmodified polyolefin wax (D-1), were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai) in the proportions shown in Table 1. The physical properties were measured by the methods described above. The results are shown in Table 1.

[0132] Comparative Example 4 Pellets of a thermoplastic resin composition and test samples were produced in the same manner as in Example 1, except that raw materials, such as a propylene polymer (A2-1), an ethylene polymer (A1-1), aluminum oxide (C2-1), and an unmodified polyolefin wax (D-1), were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai) in the proportions shown in Table 1, and the physical properties were measured by the methods described above. The results are shown in Table 1. The composition obtained in Comparative Example 4 was presumably lacking the acid-modified propylene polymer (B) and therefore had a lower affinity between the metal oxide and the resin component than the composition of Example 8. As a result, the composition had poor mechanical properties, such as low strength and hardness, and a low deflection temperature under load, such that the heat resistance was poor.

[0133] [Example 9] Pellets and test samples of a thermoplastic resin composition were produced in the same manner as in Example 1, except that raw materials, propylene polymer (A2-1), acid-modified propylene polymer (B-1), magnesium oxide (C1-2), and unmodified polyolefin wax (D-1), were introduced into a kneading apparatus (a benchtop kneader manufactured by Irie Shokai) in the proportions shown in Table 1. The physical properties were measured by the methods described above. The results are shown in Table 1.

[0134]

Claims

1. An olefin-based resin composition comprising 9.7 to 36 parts by mass of an unmodified olefin-based polymer (A), 0.3 to 15 parts by mass of an acid-modified propylene-based polymer (B), 54 to 90 parts by mass of a metal oxide (C) (wherein the total amount of the unmodified olefin-based polymer (A), the acid-modified propylene-based polymer (B) and the metal oxide (C) is 100 parts by mass), and 0.1 to 10 parts by mass of an unmodified polyolefin-based wax (D) relative to a total of 100 parts by mass of the unmodified olefin-based polymer (A), the acid-modified propylene-based polymer (B) and the metal oxide (C).

2. The olefin resin composition according to claim 1, wherein the unmodified olefin polymer (A) is at least one member selected from the group consisting of ethylene polymers, propylene polymers, 1-butene polymers, and 4-methyl-1-pentene polymers.

3. The olefin resin composition according to claim 1, wherein the metal oxide (C) includes magnesium oxide.

4. The olefin resin composition according to claim 1, wherein the thermal conductivity of the metal oxide (C) is in the range of 10 to 300 W / mK.

5. The olefin resin composition according to claim 1, wherein the thermal conductivity of the olefin resin composition is in the range of 0.5 to 5 W / mK.

6. The olefin resin composition according to claim 1, wherein the specific gravity of said olefin resin composition is in the range of 1.2 to 5.

0.

7. The olefin resin composition according to claim 1, wherein the olefin resin composition has an unsaturated carboxylic acid content in the range of 0.002 to 0.42 parts by mass per 100 parts by mass of the total of the unmodified olefin polymer (A), the acid-modified propylene polymer (B), the metal oxide (C) and the unmodified polyolefin wax (D).

8. A molded article comprising the olefin resin composition according to any one of claims 1 to 7.

9. A door handle, door knob, handrail or switch comprising the olefin resin composition according to any one of claims 1 to 7.

10. A case comprising the olefin resin composition according to any one of claims 1 to 7.

11. An electricity storage device comprising the olefin resin composition according to any one of claims 1 to 7.

12. A clothing accessory comprising the olefin resin composition according to any one of claims 1 to 7.

13. A stationery item comprising the olefin resin composition according to any one of claims 1 to 7.

14. A container, tableware or sake bottle containing the olefin resin composition according to any one of claims 1 to 7.

15. A mouse or keyboard comprising the olefin resin composition according to any one of claims 1 to 7.